Veterinary Medicine - October 2008 - (Page 544)

Urolithiasis PEER-REVIEWED developed an atonic bladder due to prolonged obstruction, place an indwelling urinary catheter with a closed collection system. (See the boxed text titled “Placing an indwelling catheter and a connection to a closed urine collection system” on page 559.) Avoid placing indwelling urinary catheters indiscriminately because of the increased risk of associated bacterial infection. number of institutions and large, private referral practices. Medical dissolution. Medical dissolution through a special diet can be used as a primary means of urolith elimination or as a secondary procedure after urolith removal by other methods to ensure that all uroliths or fragments have been eradicated. When used as a primary method of urolith Nonobstructed patients 3. Retrograde positive contrast study in the patient from elimination, medical dissolution Uroliths can be eliminated in pa- Figure 1A. Note the ﬁlling defects in the urethra where the techniques generally require feedtients without a urethral obstruction four uroliths (arrow) seen in Figure 1B are located. ing only the prescribed diet for by voiding urohydropropulsion one month beyond radiographic (see the boxed text titled “Voiding urohydroexible probe placed endoscopically next or ultrasonographic evidence of urolith propulsion in dogs and cats” on page 550), to the targeted urolith. Laser lithotripsy dissolution. Complications from obstrucsurgical removal, lithotripsy, medical uses light-ampli ed thermal energy to tion and the lack of consistent exposure dissolution, or new minimally invasive fragment uroliths through bers endo- to urine altered by diet and medication interventional radiographic and endo- scopically positioned adjacent to the se- make dissolution protocols unlikely to be scopic techniques. lected urolith.8 Ultrasonic lithotripsy uses effective for treating uroliths located in high-frequency sound waves delivered the ureter or urethra.10 Medical dissoluVoiding urohydropropulsion. Ure- to the urolith through an endoscopically tion protocols are discussed in “Speci c thral size is a limiting factor for voiding placed electronic probe. Extracorporeal urolith characteristics, treatments, and urohydropropulsion; a male cat with shock wave lithotripsy breaks up uroliths prevention” starting on page 550. urocystoliths > 1 mm in diameter is not a through focused shock waves generated candidate for this procedure unless the cat from equipment positioned outside the Increase water intake has undergone perineal urethrostomy.4,5 patient’s body. Increasing the water intake in dogs and Voiding urohydropropulsion is also a The urolith fragments produced cats is an important part of treating and poor choice for patients with a urethral through lithotripsy must be small enough preventing uroliths. Feeding a patient a obstruction, a history of recent urinary for the patient to eliminate them through canned diet or adding water to dry food bladder surgery, or an unresolved urinary voided urine, or they must be extracted increases urine volume, decreases the tract infection.6 by using suction devices or grasping concentration of urine minerals poteninstruments. The use of lithotripsy is tially involved in urolith formation, and Surgery. Depending on the location limited by a patient’s size and sex, the helps eliminate these minerals through of the uroliths, surgical intervention, availability of the specialized equipment, more frequent urination.11,12 Successful such as removing uroliths through an and the size, number, and composition dilution can be evaluated by periodically incision into the kidney, ureter, bladder, of uroliths involved. checking a patient’s urine speci c gravity or urethra or, occasionally, removing a Traditionally, intracorporeal electro- to see if it remains 11 lb (5 kg),9 and male cats cedures have enhanced the diagnosis Lithotripsy. Lithotripsy can be accom- that have had a perineal urethrostomy and removal of uroliths.16,17 Fluoroscopy, plished by intracorporeal electrohydrau- performed. Extracorporeal shock wave ultrasonography, and endoscopy are used lic, laser, or ultrasonic techniques or by lithotripsy has been used primarily for to identify and retrieve uroliths located an extracorporeal shock wave method. fragmenting nephroliths and ureteroliths virtually anywhere in the urinary tract. Intracorporeal electrohydraulic litho- in dogs only. Although laser lithotripsy This combination of methods can be used tripsy breaks up uroliths by using repeti- use is becoming more widespread, most to place stents to relieve urolith-related tive shock waves conducted through a of these techniques are limited to a small obstruction and to facilitate antegrade 544 October 2008 VETERINARY MEDICINE

Table of Contents Feed for the Digital Edition of Veterinary Medicine - October 2008

Veterinary Medicine - October 2008 Contents Leading Off Clinical Exposures Idea Exchange Stalking Stones Vaginitis in Dogs CE Form Advertiser Index Marketplace/Classifieds Mind Over Miller

Veterinary Medicine - October 2008

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